High speed, low temperature diazo processor

Abstract

A processor for developing diazo film has flat platens disposed within a housing and spaced apart a distance to accommodate the thickness of the film. The housing includes an inlet and an outlet aligned with the space between the platens and means for advancing a film from the inlet and through the space between the platens in a preheat chamber and in a developing chamber and for discharging the developed film. The platen facing the emulsion side of the film is heated in the preheat chamber so that the film is heated to a desired temperature prior to developing. A metered amount of aqueous ammonia is supplied through a lower chamber at the inlet end of the developing chamber wherein the ammonia is separated from the water by reason of the differential temperature and ammonia vapor rises to contact the emulsion side of the film for rapidly developing thereof and the water is drained from the lower chamber.

What is claimed is: 
     
       1. A diazo film developing system comprising a first chamber for preheating said film, a   second chamber for developing said preheated film,   means for heating said second chamber,   means for moving said film through said first and said second chambers,   means defining a cavity adjacent said second chamber for receiving aqueous ammonia in controlled manner, and   thermal control means comprising a heat resistant spacer element connecting said second chamber and said cavity for maintaining a temperature differential therebetween, said cavity means having a temperature lower than the temperature of said second chamber whereby said aqueous ammonia is vaporized and the ammonia vapor contacts the emulsion of said film, the temperature differential causing the ammonia to separate from the water prior to contact with said film.   
     
     
       2. The system of claim 1 wherein said first chamber includes a pair of spaced surfaces defining a path for the diazo film and a heating element for heating said surfaces. 
     
     
       3. The system of claim 1 wherein said second chamber includes a pair of spaced surfaces defining a path for the diazo film and a heating element for heating said surfaces and wherein said thermal control means comprises a plate element engaging one of said surfaces and in contact with an edge of said cavity means for controlling the flow of heat thereto. 
     
     
       4. The system of claim 1 wherein said cavity means comprises a recessed portion of said second chamber disposed at one end thereof for conveying the ammonia vapor to the film. 
     
     
       5. The system of claim 1 wherein said cavity means comprises a recessed portion of said second chamber disposed at one end thereof and wherein said thermal control means comprises a plate element engaging one of said surfaces and in contact with an edge of said cavity means to provide the temperature differential for separating ammonia from water, the water being drained from said recessed portion. 
     
     
       6. A method for developing diazo film having an emulsion on one side thereof, comprising the steps of: providing a developing chamber for passage of said film therethrough,   heating the atmosphere of said chamber to a predetermined temperature,   introducing aqueous ammonia into a lower portion of said chamber at a temperature lower than said predetermined temperature, and   placing a heat resistant spacer element between said developing chamber and said lower portion of said chamber for maintaining temperature differential therebetween for enabling said aqueous ammonia to be separated from the water and wherein the vaporized ammonia contacts the emulsion of said film.   
     
     
       7. The method of claim 6 including the step of preheating the film prior to entrance thereof into said developing chamber. 
     
     
       8. The method of claim 6 wherein the step of introducing aqueous ammonia comprises a continuous flow of ammonia into said lower portion of said chamber. 
     
     
       9. Apparatus for developing diazo film comprising: means defining a heated developing chamber and including first and second, spaced-apart, substantially parallel surfaces to provide a path for said diazo film, and a cavity portion at one end of said developing chamber,   means for moving said diazo film into and through said developing chamber with the emulsion side of said diazo film adjacent one of said surfaces,   means for introducing aqueous ammonia into the cavity portion of said developing chamber, and   thermal control means comprising a heat resistant spacer element connected with one of said surfaces and with said cavity portion for controlling the temperature therebetween, the temperature of said cavity portion being lower than the temperature of the film path through said developing chamber to enable vaporization of said aqueous ammonia whereby ammonia vapor is separated from the water and the vapor contacts the emulsion side of said diazo film.   
     
     
       10. The apparatus of claim 9 including means for preheating the diazo film to a desired temperature prior to entering the developing chamber. 
     
     
       11. The apparatus of claim 9 wherein said film moving means comprise a pair of cooperating rollers at each end of the developing chamber. 
     
     
       12. The apparatus of claim 9 wherein said cavity portion comprises a separate chamber disposed at one end of said developing chamber and open across the top for communication with the emulsion side of said diazo film. 
     
     
       13. The apparatus of claim 9 wherein said aqueous ammonia introducing means includes a pump for conveying a continuous flow of aqueous ammonia into the cavity portion of said developing chamber at approximately ambient temperature. 
     
     
       14. The apparatus of claim 9 including means for preheating the diazo film to a desired temperature and means for heating one of said surfaces of said developing chamber for providing a temperature differential between the cavity portion and the developing chamber whereby ammonia vapor is separated from the water and contacts the emulsion side of said diazo film.